Third International Conference on Spoken Language Processing (ICSLP 94)

Yokohama, Japan
September 18-22, 1994

Cortical Activation with Speech in Cochlear Implant Users: A Study with Positron Emission Tomography

Yasushi Naito (1), Hidehiko Okazawa (2), Iwao Honjo (1), Yosaku Shiomi (1), Haruo Takahashi (1), Waka Hoji (1), Michio Kawano (3), Hiroshi Ishizu (2), Sadahiko Nishizawa (2), Yoshiharu Yonekura (4), Junji Konishi (2)

(1) Department of Otolaryngology, Kyoto University, Faculty of Medicine, Kyoto, Japan
(2) Nuclear Medicine, Kyoto University, Faculty of Medicine, Kyoto, Japan
(3) Department of Developmental Disorder, Kyoto University of Education, Kyoto, Japan
(4) Brain Pathophysiology, Kyoto University, Faculty of Medicine, Kyoto, Japan

The objective of this study is to investigate the pattern of cortical activation associated with speech sound stimulation in cochlear implant (CI) users. Six postlingually deaf patients using CIs were examined with positron emission tomography (PET) using intravenous injection of 15-O labeled water. PET activation studies were performed in two sets of three different conditions; (1) no sound stimulation as control, (2) hearing white noise and (3) hearing sequential words. Under sequential words' stimulation, regional cerebral blood flow (rCBF) in the primary auditory cortex, the auditory integration region and the auditory association area increased from the base line value. In contrast, white noise stimulation resulted in an increase of rCBF only in the primary auditory and auditory integration regions, and the increase was less than that observed in word stimulation. These results suggest that, in spite of non-physiological stimulation of the auditory primary afferents, speech being input through CIs are processed in the ordinary auditory cortices.

Full Paper

Bibliographic reference.  Naito, Yasushi / Okazawa, Hidehiko / Honjo, Iwao / Shiomi, Yosaku / Takahashi, Haruo / Hoji, Waka / Kawano, Michio / Ishizu, Hiroshi / Nishizawa, Sadahiko / Yonekura, Yoshiharu / Konishi, Junji (1994): "Cortical activation with speech in cochlear implant users: a study with positron emission tomography", In ICSLP-1994, 2035-2038.